In the field of plastic surgery, various substances and techniques are being developed in the area of cosmetic rejuvenation, for, inter alia, relieving facial aging and wrinkling. Current techniques involve the implantation of foreign substances into the affected areas of the recipient. Two foreign substances currently being used in this area are collagen and synthetic materials. Collagen implants involve the injection of the protein substance of the white fibers of (collagenous fibers) of connective tissue, such as skin, tendon, bone and cartilage. Current synthetic implants involve the injection of silicone, cadaver skin, and other synthesized materials. However, collagen and synthetic implants have various downsides, including infection, inflammation, rejection by the recipient, and limited durability of the injected materials. In an effort to eliminate these and other downsides associated with implanting collagen, synthetic or other foreign materials, fat transplantation (or transplantation of fat or fat tissue or cells) is being regarded as the future mainstay of cosmetic rejuvenation.
Fat transplantation involves: (a) harvesting fat tissue, along with other substances surrounding it from a harvesting site; (b) preparing the fat tissue; and then (c) injecting the fat tissue into the affected areas in the recipient. Fat tissue resides in the human body together with blood vessels, and other naturally occurring substances. In order to harvest the fat tissue, a tumescent fluid is first injected into the harvesting site, which may be, e.g., another part of the recipient's body. The tumescent fluid swells or increases the volume of the tissue in the harvesting site, thus reducing blood loss during harvesting, and facilitating the removal of the tissue from the harvesting site. Tumescent fluid currently includes a mixture of salt solution, epinephrine and lidocaine, although other substances may be used in order to accomplish the same effect on the fat tissue. A mixture of fat tissue, tumescent fluid, and oil (created by the body as a result of harvesting trauma), is then harvested from the site under low vacuum pressure into harvesting syringes through specially designed cannulae inserted into the site.
In order to prepare the fat tissue for injection, it must be separated from the other harvested substances in the mixture inside the syringe. Automated centrifuges have been used to segregate the mixture into the three layers of oil, fat tissue (or the fatty layer in the syringe), and tumescent fluid within each harvesting syringe. These automated centrifuges often rotate the harvesting syringes at a rate much higher than needed in order to segregate this type of mixture into its various layers, thus subjecting the tissue to unnecessary manipulation and trauma. Furthermore, since there is no easy, cost-effective way of maintaining the cleanliness of the automated centrifuges (and in particular, the surfaces surrounding the harvesting syringes), the sterility of the environment surrounding the fat tissue is often compromised.
The segregated mixture then needs to be further manipulated in a variety of ways in order to remove the oil and tumescent fluid layers, isolate and clean the fat tissue or fatty layer, and transfer the fat tissue to smaller syringes, e.g., 1 cc syringes, for transplantation. The various manipulation techniques involve rotating the mixture and moving it from one container to another. For example, the harvesting syringe containing the segregated mixture may be flipped around, first to place the tumescent fluid layer on top and decant the tumescent fluid from the mixture, and then to place the oil layer on top and decant the oil from the mixture. The fat tissue may then be injected into another container to be washed, and then injected into the smaller transplantation syringes, so that it may then be injected into the desired location. Each of these manipulations exposes at least some of the mixture and the fat tissue therein to air, in addition to bringing the mixture and tissue into contact with additional instruments and surfaces, and causing other trauma to the tissue. Each exposure to air reduces the viability of the fat tissue, and increases the risk of contamination.
Each manipulation of the mixture, and the fat tissue contained therein, affects the long term results of the transplantation, by comprising the sterility of the tissue and its surrounding environment, and subjecting the tissue to additional unnecessary trauma. The compromised sterility increases the chances of infection, inflammation and rejection of the fat transplant. The unnecessary trauma affects the viability and integrity of the fat tissue, and reduces the durability of the transplant. These effects, together with the high cost of the instruments involved in the process, decrease the desirability of using fat transplants for cosmetic rejuvenation.